Preservative compositions based on iodopropynl- and formaldehyde donor compounds

ABSTRACT

Compositions having broad effectiveness against bacteria and fungi, which comprise (a) an iodopropynylbutyl compound and (b) one or more formaldehyde donor compounds, the formaldehyde donor compounds being N-formals, O-formals and/or a combination thereof. The compositions are also stable and effective in the form of liquid concentrates. The present invention also relates to the use of such compositions in industrial products and to industrial products which comprise these compositions.

CROSS REFERENCE TO RELATED APPLICATION

This is the 35 USC 371 national stage of international applicationPCT/IB98/00766 filed on May 19, 1998, which designated the United Statesof America.

FIELD OF THE INVENTION

The present invention relates to compositions or preservatives for usein industrial products, which protect these products against bacterialand fungal infestation over extended service lives.

BACKGROUND OF THE INVENTION

Preservatives having a biocidal action for use in industrial productssuch as cutting fluids, cutting fluids which have been mixed with water,industrial emulsions or other water-based industrial products, and alsofor household products, such as, for example, cleaning products orcosmetics, such as, for example, bodycare products, are when requiredgenerally added to the products to be preserved in low concentration inthe form of concentrates.

They protect these products against infestation by bacteria, fungi andyeasts and contribute to long service lives of industrial products, suchas, for example, cutting fluids which have been mixed with water, and toa long useful life of household products and cosmetic products.

During their manufacture, storage and their use, preservatives aresubject to certain requirements which arise inter alia from the way inwhich they are added to the abovementioned products in the form ofliquid concentrates.

A known fungicidal active ingredient which is frequently used today isiodopropynylbutyl carbamate (IPBC), which is marketed, for example, byTroy Chemie as an organic fungicide preparation in the form of a 20%strength solution of the active ingredient in glycols under the tradename Troyshield F20.

In order to achieve a likewise satisfactory bactericidal effect, it is,however, necessary to combine IPBC with other active substances, e.g.formaldehyde donor compounds. Regarding compatibility with IPBC,however, there are problems when used in concentrates containingformaldehyde donor compounds in the form of strongly alkalinebactericides. Thus, for example, Troy Chemie's technical instructionsheet for Troyshield F20™ advises against mixing it with stronglyalkaline bactericides, such as, for example,1,3,5-tris(hydroxyethyl)hexahydrotriazine (Grotan BK™), because thestability of fungicidally and bactericidally active preparations basedon IPBC is impaired.

There has thus been a search for potential ways of improving thestability of IPBC-based compositions for use as preservatives having afungicidal and bactericidal action.

The prior art includes, for example, an almost white powder consistingof IPBC and a mixture of 1,3-bis(hydroxymethyl)-5,5-dimethylhydantoinand hydroxy-methyl-5,5-dimethylhydantoin GlydantPlus™, Lonza AG), whichis used as a preservative for cosmetic preparations.

U.S. Pat. No. 5,496,842 and U.S. Pat. No. 5,428,050 disclosewater-soluble compositions comprising a combination of iodopropynylbutylcompounds and N-methylol compounds. It is disclosed that compositionscomprising IPBC and N-methylol compounds in a weight ratio of from 1:100to 1:2000 are in the form of a concentrate powder which, as awater-soluble additive, can be added to industrial products, inparticular bodycare products, which then include from 0.01% to 2% ofthese compositions. The N-methylol compounds mentioned in U.S. Pat. No.5,496,842 and U.S. Pat. No. 5,428,050 do, however, include compoundswhich are not compatible with IPBC, for example1,3,5-tris(hydroxyethyl)-hexa-hydrotriazine.

EP 0327220 B1 discloses a combination of an iodopropynyl compound withknown formaldehyde donors. The disclosed compositions include, aspreferred iodopropynyl compound, IPBC and, as formaldehyde donors,non-toxic and odorless compounds which are suitable for use in bodycareproducts, for example urea derivatives and dimethyloldimethylhydantoin.The compositions of EP 0327200 B1 are likewise added, for example, inthe form of solid, water-soluble mixtures, to the products to bepreserved.

The known pulverulent concentrates do, however, have a number oftechnical disadvantages, such as, for example, a tendency towardclumping, a relatively low dissolution rate, a tendency to form dust andthe like.

Moreover, the use of odourless, i.e. usually nonvolatile, formaldehydedonors does not, in the case of certain applications, offer adequateantimicrobial protection in the gaseous phase, since no vapour phase ofvolatile, formaldehyde compounds is present.

In addition, the N-methylols in the form of liquid concentratesmentioned in U.S. Pat. No. 5,496,842 and U.S. Pat. No. 5,428,050 are notcompatible with IPBC, i.e. are unstable and are thus also insufficientlystable in liquid products, such as cutting fluids, which are to bepreserved. This is therefore a disadvantage particularly because inindustrial products such as cutting fluid emulsions, desired pHstabilization and buffering is achieved inter alia by adding basic,tertiary amines.

SUMMARY OF THE INVENTION

The object of the present invention is to provide compositions whichprotect industrial products against bacterial attack and fungalinfestation over extended service lives. The novel compositions shouldthemselves be sufficiently stable and should not decompose under variousconditions. In addition, they should be easy to handle and haveadvantageous technical properties and be easily incorporated intoindustrial products.

Another object of the present invention is to provide biocidalcompositions which include iodopropynylbutyl compounds and formaldehydedonor compounds which are compatible therewith. It should be possible tometer these compositions into standard commercial industrial products,for example by adding a liquid preparation.

Another aim of the present invention is to provide compositions whichhave improved vapour phase effectiveness compared with the prior art andare sufficiently stable over a wide pH range.

A further object of the present invention is to provide industrialproducts, such as, for example, cutting fluids, which are distinguishedfrom the prior art by increased stability and improved effectiveness.

This object is achieved by a composition which includes (a) aniodopropynylbutyl compound selected from iodopropynylbutyl esters,ethers, acetals, carbamates and carbonates and (b) one or moreformaldehyde donor compounds, and is characterized in that theformaldehyde donor compounds are N-formals formed by the reaction orcondensation of a monovalent or polyvalent, amino-substitutedC₁-C₁₀-alkyl, -aryl or -aralkyl alcohol and a formaldehyde-supplyingcompound, and/or O-formals formed by the reaction of a monovalent orpolyvalent C₁-C₁₀-alkyl, -aryl -aralkyl alcohol or of a glycol or glycolether and a formaldehyde-supplying compound, and/or a combinationthereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments are the subject-matter of the dependent claims.

The novel preparations preferably comprise iodopropynylbutyl carbamate(IPBC), and the formaldehyde donor compound is preferably an N-formalselected from 3,3′-methylenebis(5-methyloxazolidine) (Mar 71™),3,3′-methylenebis(tetrahydro-2H-1,3-oxazine) and1-aza-5-ethyl-3,7-dioxabicyclo-(3,3,0)octane, particularly preferably acombination of 3,3′-methylenebis(5-methyloxazolidine) (Mar 71™) andIPBC.

The compositions comprising the novel iodopropynylbutyl compound andN-formals include the components in amounts, based on the composition,of from 0.1 to 20% by weight of iodopropynylbutyl compound and from 99.9to 80% by weight of N-formal, preferably from 1 to 10% by weight ofiodopropynylbutyl compound and from 99 to 90% by weight of N-formal. Thecomposition particularly preferably comprises from 4 to 6% by weight ofiodopropynylbutyl compound, in particular iodopropynylbutyl carbamate,and from 96 to 94% by weight of N-formal, in particular3,3′-methylenebis(5-methyloxazo-lidine).

In addition or alternatively to the N-formals according to theinvention, the novel compositions may also comprise O-formals formed bythe reaction or condensation of formaldehyde-supplying compounds andmono- or polyvalent C₁-C₁₀-alkyl, -aryl or -alkaryl alcohols or glycolsor glycol ethers, such as, for example, 1,2-propylene glycol hemiformal,ethylene glycol mono- and/or bisformal, butyldiglycol hemiformal,butylglycol hemiformal, benzyl glycol hemiformal, dipropylene glycolhemiformal and the like.

The compositions comprising the iodopropynylbutyl compound according tothe invention and O-formals include the components in amounts, based onthe composition, of from 0.1 to 20% by weight of iodopropynylbutylcompound and from 99.9 to 80% by weight of O-formal, preferably from 1to 10% by weight of iodopropynylbutyl compound and from 99 to 90% byweight of O-formal. The composition particularly preferably comprisesfrom 4 to 6% by weight of iodopropynylbutyl compound, in particulariodopropynylbutyl carbamate and from 96 to 94% by weight of O-formal, inparticular from 96 to 94% by weight of 1,2-propylene glycol hemiformal.

Particularly suitable compositions are also those which comprise from0.1 to 20% by weight, of an iodopropynylbutyl compound and from 99.9 to80% by weight of a mixture of N- and O-formals, the weight ratio of N-to O-formals being from 10:1 to 1:10, preferably from 9:1 to 8:2 andparticularly preferably from 2:1 to 1:2. These compositions preferablycomprise from 1 to 10% by weight of iodopropynylbutyl compound and from99 to 90% by weight of the mixture of N- and O-formals. Such acomposition particularly preferably comprises from 4 to 6% by weight ofiodopropynylbutyl compound, in particular iodopropynylbutyl carbamate,and from 96 to 94% by weight of the mixture of N- and O-formals, inparticular from 96 to 94% by weight of a mixture of3,3′-methylenebis(5-methyloxazolidine) and 1,2-propylene glycolhemiformal.

The novel compositions are preferably in stable liquid, viscous liquidor paste form, so that they are easy to handle and can be added easilyto an industrial product at any time in order to preserve it.

In addition to the biocidally effective components, the novelcompositions may comprise further additives and/or auxiliaries, such asemission-reducing additives, viscosity-modifying additives, wettingagents and solvents which have a favourable effect on the technicalproperties of the compositions, such as, for example, solubility inwater, in total amounts of less than 90% by weight, preferably of lessthan 30% by weight and particularly preferably of less than 15% byweight. Here, the mixing ratios of the individual additives to oneanother are in the customary ranges known for biocidal compositions.

Particularly suitable compositions are those which comprise a solventwhich is selected from 1,2-propylene glycol, 1-methoxy-2-propanol,phenoxypropanol and phenoxyethanol.

For example, the addition of certain glycols, preferably 1,2-propyleneglycol, in amounts of from 1 to 20% by weight, based on the composition,has a positive influence on the odour of the compositions and reducesthe emission of readily volatile substances, such as, for example,formaldehyde.

Particularly suitable compositions are those which, based on thecomposition, include the following components:

a) from 0.1 to 20% by weight, preferably from 1 to 10% by weight andparticularly preferably from 4 to 6% by weight, of an iodopropynylcompound according to the invention and

b) from 99.8 to 80% by weight, preferably from 99 to 90% by weight andparticularly preferably from 96 to 94% by weight, of a mixture ofsolvents and N-formals according to the invention or of a mixture ofsolvents and O-formals according to the invention or of a mixture of acombination of N- and O-formals and solvents and also other additives asdescribed above, the weight ratio of formal to a solvent being from 50:1to 1:10 and preferably greater than 9:1.

As well as the described additives and solvents, which contribute toimproving the properties of the novel compositions, the latter maycomprise further known biocidal active ingredients, such as, forexample, isothiazolones or mercaptopyridines, of whichN-octylisothiazolone (Kathon 893™) and 2-mercaptopyridine N-oxide, inparticular in the form of its 40% strength aqueous sodium salt solution(Pyrion-Na ™), are particularly preferred;

The composition may also comprises further additives which improve itsstability.

In a specific embodiment of the present invention, the composition, asdescribed above? comprises between 1% and 10% by weight of IPBC, between85% and 98,5% by weight of 3-3′-methylene bis (5-methyloxazolidine) andbetween 0,5% and 5% by weight of a stabilizer selected fromtriethanolamine, pyriondisulfide, sodium sulfate or aluminium oxide.

The novel compositions are in the form of a stable liquid concentrate, astable working solution prepared by diluting the concentrate, a stableemulsion or a stable suspension. The composition can thus be meteredeasily and also has a good shelf life and does not decompose underpractical conditions. The good handling properties of the composition,compared with the storage, preparation and metering in of activeingredients present in two-component systems, are advantageous.

In particular, the novel composition is in the form of a concentrate, inwhich case the following requirements placed on concentrates aresatisfied:

broad effectiveness (e.g. against bacteria, yeasts and fungi)

storage stability, transportation stability and thermal stability

relative insensitivity towards heat and light

compatibility with packing materials

adequate solubility in water and homogeneous distribution properties toachieve problem-free incorporation in the products to be preserved (e.g.aqueous solutions or hydrous products)

good incorporation into anhydrous or low-water products

vapour phase effectiveness

adequate pH compatibility, in particular up to pH 11

sufficiently low viscosity to enable simple metering.

The novel compositions may effectively be added to industrial productscontaining industrial preservatives, in particular containerpreservatives, fuel additives, cutting fluid preservatives,preservatives for cutting fluids which have been mixed with water,emulsions and dispersions in the coatings industry or in metalworking,household products, cosmetics and the like, so that the stabilitythereof and the service life of the finished products is increasedcompared with known systems. Increased stability of the novelcompositions is particularly apparent from the lower tendency of theactive ingredient to decompose, less discoloration and reduced formationof undefined decomposition products.

In addition to the customary constituents, the abovementioned industrialproducts thus comprise a novel composition whose components aresufficiently compatible both in the concentrate and also in the emulsionor suspension. The industrial products preferably comprise from 1 to 10%by weight, preferably from 2 to 5% by weight and in particular 2% byweight, of the novel composition.

Surprisingly, it has been found that the novel combinations ofiodopropynylbutyl compounds and N- and/or O-formals, in particular thecombination of iodopropynylbutyl carbamate (IPBC) and3,3′-methylenebis(5-methyloxazolidine) (Mar 71™), have a stability whichis significantly improved over the prior art, even if they are presentin the form of liquid compositions, such as, for example, solutions oremulsions, in particular liquid concentrates, and are added to theabovementioned industrial products in such a form.

In addition, the effectiveness of the compositions is improved by theaddition of further additives as in Patent claims 15 to 23, and, inparticular, it is also possible to improve the effectiveness in thevapour phase.

Moreover, the novel compositions are adequately stable over sufficientlybroad pH ranges which are relevant when the compositions are used inindustrial products. Their stability is adequate in the pH range up to12, in particular in the range up to pH 11, especially up to pH 9.

The improvements achieved in the compositions as regards stability,effectiveness and other technically relevant properties, such as pHstability and emission behaviour, are illustrated by the examples below.

EXAMPLES

The following abbreviations are used in the examples below:

IPBC = iodopropynylbutyl carbamate Mar 71 ™ =3,3′-methylenebis(5-methyloxazolidine) Grotan BK  ™ =1,3,5-tris(hydroxyethyl)hexahydrotriazine BDG = butyldiglycol POE =phenoxyethanol DPG = dipropylene glycol PM = 1-methoxy-2-propanol PP =phenoxypropanol Kathon 893 ™ = 45% strength N-octylisothiazolonesolution in 1,2-propylene glycol PE = polyethylene PLG = propyleneglycolPreventol D2 ™ = benzyl alcohol hemiformal

Example 1

Compositions of IPBC and Mar 71™ with and without 1,2-propylene Glycolas Solvent

In a test series, compositions based on (90−x)% by weight of Mar 71+x %by weight of IPBC+10% by weight of 1,2-PLG were prepared. TheIPBC-containing mixtures were slightly cloudy and had to be filtered togive clear, colourless to pale yellow solutions, which were stored at atemperature of +40° C. in clear glass in order to test the stability ofthe compositions.

Table I shows the development, determined by means of HPLC, of the IPBCconcentration of the solutions with time over a period of 3 months.Investigations were carried out on solutions having an IPBC startingcontent of from 0 to 10% by weight.

TABLE I IPBC contents: [% by wt.] 1 3 5 10 After 1 month at +40° C. 0.762.35 3.83 7.40 After 2 months at +40° C. — 0.62 1.88 3.04 5.66 After 3months at +40° C. 0 0.52 1.53 2.49 4.50 —

In a second test series, compositions based on (100−x) % by weight ofMar 71™+x % by weight of IPBC without the addition of 1,2-PLG wereprepared. The IPBC-containing mixtures were likewise slightly cloudy andwere therefore filtered to obtain colourless to pale yellow solutions.These solutions were stored in clear glass at a temperature of +40° C.over three months. The development with time of the IPBC contents,determined by means of HPLC, is given in Table II for IPBC startingcontents of from 0 to 10% by weight. The stability of the compositionsin the absence of 1,2-PLG is negligibly greater, although in both casesthe stability of the compositions is adequate over a sufficiently longstorage period.

Furthermore, the formaldehyde emission was measured using a Dräger tubeafter storage for about three months at a temperature of +40° C. Theformaldehyde emission was determined using Dräger tubes 67 33 081 inaccordance with Dräger instructions for use no. 234-33081 (DrägerwerkAG, Germany), which involved in each case carrying out 10 strokes at 21°C. over a 50 ml wide-necked glass containing 5 g of the sample to beinvestigated. It was found that the formaldehyde emission increases withincreasing IPBC content, as the results in the last line of Table IIshow. The biocidal effectiveness of the compositions in the gas phasethus also increases with increasing IPBC content in an advantageousmanner.

TABLE II IPBC contents; [% by wt.] 0 1 3 5 10 After 1 month at +40° C. —0.75 2.17 3.71 7.08 After 2 months at +40° C. — 0.64 1.85 3.06 5.63After 3 months at +40° C. — 0.58 1.68 2.69 4.87 Formaldehyde emission 35 6-7 7 8 [ppm]

Example 2

Compositions of IPBC and various N-formals

The stability and compatibility of IPBC in compositions containing 3% byweight of IPBC, from 80 to 97% by weight of N-formals and 17% by weightof 1,2-PLG were determined as a function of the storage time after thesolutions had been stored at a temperature of +40° C. in clear glass. Asummary of the various percentages in the compositions is given in TableIII.

The initially clear, colourless to slightly yellowish solutions becamediscoloured to varying degrees after storage for three months at atemperature of +40° C. Only the compositions based on IPBC and Mar 71retained their clear, slightly yellowish appearance.

In all samples, the odour was characteristic, in some cases beingpungent from the formaldehyde, and in others being amine-like.Composition F had a considerably weaker odour than composition E, whichhad a characteristic pungent formaldehyde odour.

TABLE III Composition in % by wt. A B C D E F G H Grotan BK ™ 97 80Isopropanolamine-Grotan BK 97 80 with amine-excess Mar 71 ™ 97 80 Mar71 ™ variant 97 80 with amine excess, not dewatered IPBC  3  3  3  3  3 3  3  3 1,2-PLG — 17 — 17 — 17 — 17 Colour after 3 months at +40° C. Aand B; clear red-brown C and D: clear, red     E and F: clear, yellowishG and H: clear, red    

A summary of the development of the IPBC content, determined by means ofHPLC (IPBC starting content 3% by weight) in the compositionsinvestigated as a function of the storage period, is given in Table IV.

TABLE IV IPBC Contents [% by wt.] A B C D E F G H After 1 month <0.030.03 <0.03 <0.03 2.44 2.27   0.73 0.94 After 2 months <0.03 2.04 1.78  0.53 0.72 After 3,5 1.61 1.34 <0.01 0.04 months

It is found that IPBC is compatible with different N-formals to varyingdegrees. Incompatibility is apparent in particular from a relativelyhigh degree of discoloration following storage and a relatively highdegree of IPBC degradation. Thus, for example, the low-odour Grotan BK™is incompatible with IPBC. In contrast, preparations based on IPBC andMar 71™ with or without 1,2-PLG are significantly more stable and, afterstorage for three months at +40° C. display on IPBC degradation of onlyabout 50%. The formaldehyde emission increases with increasing IPBCcontent. The addition of 1,2-PLG to compositions which comprise Mar 71and IPBC is therefore unfavourable for the stability, but has anadvantageous effect on the odour of the compositions.

Example 3

Stability of IPBC and Mar 71 in Various Solvents

The dependence of the IPBC stability in compositions of IPBC and Mar 71™on various solvents used was tested by storing the compositions in clearglass at a temperature of +40° C. Investigations were carried out onpreparations containing 1 or 3% by weight of IPBC combined with 89 or87% by weight of Mar 71™ respectively and in each case 10% by weight ofa solvent. The results are given in Tables V and VI.

TABLE V Composition [% by wt.] A C E G I K Mar 71 89 89 89 89 89 89 IPBC1 1 1 1 1 1 1,2-PLG 10 — — — — — DPG — 10 — — — — BDG — — 10 — — — PM —— — 10 — — POE — — — — 10 — PP — — — — — 10 IPBC Content [% by wt.]After 1 month at +40° C. 0.74 0.75 0.74 0.77 0.76 0.75 After 2 months at+40° C. 0.63 0.66 0.61 0.62 0.57 0.68 After 3 months at +40° C. 0.560.57 0.54 0.60 0.60 0.60 Formaldehyde emission* 4 5 3 2 5 5 (in ppm) * =measured as described in Example 1 using Dräger tubes (10 strokes) at21° C. after storage for about 3 months at +40° C. on 5 g in each casein a 50 ml wide-necked glass.

TABLE VI Composition [% by wt.] B D F H J L Mar 71 87 87 87 87 87 87IPBC 3 3 3 3 3 3 1,2-PLG 10 — — — — — DPG — 10 — — — — BDG — — 10 — — —PM — — — 10 — — POE — — — — 10 — PP — — — — — 10 IPBC Content [% by wt.]After 1 month at +40° C. 2.12 2.20 2.15 2.21 2.21 2.17 After 2 months at+40° C. 1.72 1.75 1.89 1.90 1.84 1.77 After 3 months at +40° C. 1.501.57 1.47 1.57 1.52 1.57 Formaldehyde emission* 5 6 6-7 4 6 8 (in ppm) *= measured as described in Example 1 using Dräger tubes (10 strokes) at21° C. after storage for about 3 months at +40° C. on 5 g in each casein a 50 ml wide-necked glass.

It has been found that the IPBC content of the preparations, determinedby means of HPLC, continually decreases throughout the storage time. Theeffect of the solvent on the IPBC stability in the presence of Mar 71 isnot very great. All investigated compositions showed an IPBC degradationof about 50% after storage for 3 months in clear glass at +40° C. Inboth test series, the greatest IPBC degradation was in butyldiglycol(BDG). In contrast, relatively suitable solvents for the novelcompositions are: dipropylene glycol (DPG), 1-methoxy-2-propanol (PM),phenoxypropanols (PP) and phenoxyethanol.

There were clear differences in the formaldehyde emission determination.As Tables V and VI show, a composition containing 1-methoxy-2-propanolperforms particularly well. For example, compared with all the othersolvents, the formaldehyde emission was reduced by up to about 50% afterthree months through the addition of 1-methoxy-2-propanol.

Example 4

Stability of IPBC with Various Formals

The stabiliy of various IPBC compositions was tested in clear glass attemperatures of +25° C. and +40° C. Investigations were carried out withpreparations containing 10% by weight of IPBC and 90% of formals. Theresults are given in Tables VII and VIII.

TABLE VII Composition [% by wt.] M N O IPBC 10 10 10 Mar 71 ™ 90 — —Preventol D2 ™ — 90 — PLG hemiformal — — 90

TABLE VIII IPBC loss of weight [% wt.] after 5 weeks after 5.5 weeksafter 6.5 weeks after 3 months composition at 25° C. at 40° C. at 25° C.at 40° C. at 25° C. at 40° C. at 25° C. M — — — — 1.49 19.13 — — N 6.431.1 — — — — — — O — — 26.25 64.90 — — 58.33 69.79

Example 5

Stability of IPBC Compositions Containing further Additives

Various additives were added to the compositions M and N and thestability of the resulting preparations were investigated as hereabovementioned in example 7; the results are given in tables IX and X.

TABLE IX Composition [% by wt.] MI M2 M3 M4 N1 IPBC 10 10 10 10 10 Mar71 ™ 88 88 88 88 — Preventol D2 ™ — — — — 88 Triethanolamine  2 — — —  2Pyriondisulfide ™ —  2 — — — Anhydrous sodium sulfate — —  2 — —Aluminium oxide 90 ™ (Merck) — — —  2 —

TABLE X IPBC loss of weight [% wt.] after 5 weeks after 6,5 weeksComposition at 25° C. at 40° C. at 25° C. at 40° C. M — — 1,49 19,13 M1— — 3,93 22,85 M2 — — 0,0  15,84 M3 — — 3,83 22,0  M4 — — 1,93 13,79 N6,4 31,1 — — N1 2,5 15,8 — —

Example 6

Odour Modification of Mar 71™ by the Addition of O-formals

Compositions containing Mar 71™ with and without 1, 2, 5 and 10% byweight of 1,2-propylene glycol hemiformal were stored at roomtemperature in clear glass. The preparations proved to be sufficientlystable. However, over time a very slightly cloudy sediment formed in themixtures. The addition of 1,2-propylene glycol hemiformal resulted in aclear positive odour modification of Mar 71™.

Example 7

Compositions Based on Mar 71™ Containing Other Biocides

The stability of compositions which, in addition to 83−x % by weight ofMar 71™, comprise as further biocide 17% by weight ofN-octalisothiazolone (i.e. a 45% strength N-octylisothiazolone solutionin 1,2-PLG=Kathon 893), was tested by storage in clear glass at roomtemperature. As well as Mar 71™ and Kathon 893™, the formulations insome instances comprised 1, 2, 5 and 10% by weight of 1,2-propyleneglycol hemiformal. The preparations were found to be stable. In contrastto the compositions without Kathon 893™, no cloudy sediment formed here.The addition of 1,2-propylene glycol hemiformal resulted in a clearpositive odour modification of Mar 71™.

Example 8

Stability of Compositions Containing IPBC and Various N-formals

The stability of a composition containing 3% by weight of IPBC, 80% byweight of Mar 71™ and 17% by weight of 1,2-PLG was determined by storagein polyethylene at room temperature and at +40° C. The compositionstored at room temperature was unchanged, i.e. clear and colourless,after 14 months. The IPBC contents of the investigated compositions,determined by means of HPLC, are given in Table VII. The test provesthat the combination of Mar 71™+IPBC+1,2-PLG is sufficiently stable atvarious temperatures.

TABLE XI RT +40° C. IPBC content [% by wt] after 1 2.63 2.32 month IPBCcontent [% by wt] after 3 2.59 1.28 months IPBC content [% by wt] after8 2.22 0.59 months

As well as Mar 71™, the compatibility of IPBC with3,3′-methylenebis(tetrahydro-2H-1,3-oxazine) as a further N-formal wasinvestigated. In addition to IPBC (3% by weight) and the correspondingN-formal (80% by weight), both compositions also additionally comprise17% by weight of 1,2-propylene glycol. The IPBC content was determinedafter storage at room temperature after 1, 3 and 11 months. It has beenfound that a combination of IPBC and3,3-methylenebis(tetrahydro-2H-1,3-oxazine) is also sufficiently stable.As Table VIII shows, the IPBC content was still 2.09% by weight afterstorage for 11 months at room temperature, if 3,3′-methylenebis(tetrahydro-2H- 1,3-oxazine) was used as N-formal.

TABLE XII Composition [% by wt.] C1 D C2 Mar 71 ™ 80 — 803,3′-Methylenebis(tetrahydro- — 80 — 2H-1,3-oxazine IPBC  3  3  31,2-PLG 17 17 17 — — — IPBC content zero value — —    2.92 IPBC contentafter 1 month at RT — —    2.88 IPBC content after 3 months at RT   2.29   −2.81 — IPBC content after 11 months at RT —    2.09 —

Example 9

Formaldehyde Emission of N-formals

As well as characterizing their compatibility and stability with IPBC,the N-formals Mar 71™ and 3,3′-methylenebis(tetrahydro-2H-1,3-oxazine)were tested with regard to their formaldehyde emission behaviour andodour.

For this purpose, 1 g of each of the N-formals was left to standovernight in a 400 ml beaker covered with para-film. On the followingday, the formaldehyde content was then measured using Dräger tubes (10strokes) as described in Example 1.

The formaldehyde content was 15 ppm (2 strokes 3 ppm) in3,3′-methylenebis(tetrahydro-2H-1,3-oxazine) and 25 ppm (2 strokes 5ppm) in Mar 71™. Preparations of 80% by weight of each N-formal and 20%by weight of 1,2-propylene glycol display a clearly different behaviour.For example, the addition of 1,2-PLG to3,3′-methylenebis(tetrahydro-2H-1,3-oxazine) leads to a reduction in theformaldehyde content to form 1.5 to 2.5 ppm (20 strokes) and theaddition to Mar 71™ to a reduction to 10 ppm (5 strokes 5 ppm), theformaldehyde content being determined as described above for pureN-formals. The experiment shows that the addition of propylene glycolsignificantly reduces the formaldehyde emission of the N-formalsaccording to the invention.

What is claimed is:
 1. Composition having broad effectiveness againstbacteria and fungi, which comprises: (a) from 0.1% to 20% by weight ofiodopropynylbutyl compound selected from iodopropynylbutyl esters,ethers, acetals, carbamates and carbonates; and (b) from 80% to 99.9% byweight of either 1,2-propyleneglycol hemiformal, or a mixture of1,2-propyleneglycol hemiformal and a N-formal selected from3,3′-methylene bis(5-methyloxazolidine ), 3,3′-methylenebis(tetra-hydro-2H-1,3-oxazine) and 1-aza-5-ethyl-3, 7-dioxabicyclo(3,3,0) octane; said composition having a weight ratio of N-formal toO-formal ranging from 10:1 to 1:10.
 2. The composition according toclaim 1, which comprises: (a) from 1% to 10% by weight ofiodopropynylbutyl compound selected from iodopropynylbutyl esters,ethers, acetals, carbamates and carbonates; and (b) from 90% to 99% byweight of either 1,2-propyleneglycol hemiformal, or a mixture of1,2-propyleneglycol hemiformal and a N-formal selected from3,3′-methylene bis (5-methyloxazolidine), 3,3′-methylene bis(tetra-hydro-2H-1,3-oxazine) and 1-aza-5-ethyl-3,7-dioxabicyclo (3,3,0)octane; said composition having a weight ratio of N-formal to O-formalranging from 10:1 to 1:10.
 3. The composition according to claim 2,which comprises: (a) from 4% to 6% by weight of iodopropynylbutylcompound selected from iodopropynylbutyl esters, ethers, acetals,carbamates and carbonates; and (b) from 94% to 96% by weight of either1,2-propyleneglycol hemiformal, or a mixture of 1,2-propyleneglycolhemiformal and a N-formal selected from 3,3′-methylene bis(5-methyloxazolidine), 3,3′-methylene bis (tetra-hydro-2H-1,3-oxazine)and 1-aza-5-ethyl-3,7-dioxabicyclo (3,3,0) octane; said compositionhaving a weight ratio of N-formal to O-formal ranging from 10:1 to 1:10.4. The composition according to claim 1, wherein the weight ratio ofN-formal to O-formal is from 2:1 to 1:2.
 5. The composition according toclaim 1, wherein the iodopropynylbutyl compound is iodopropynylbutylcarbamate (IPEC).
 6. The composition according to claim 1, wherein theN-formal is 3,3′-methylene bis(5-methyloxazolidine).
 7. The compositionaccording to claim 1, wherein said composition is in stable liquid,viscous liquid or paste form.
 8. The composition according to claim 1,wherein said composition also comprises at least one ofemission-reducing additives, viscosity-modifying additives, wettingagents, stabilizers and solvents.
 9. The composition according to claim1, wherein the composition comprises solvents.
 10. The compositionaccording to claim 9, wherein the solvent is selected from 1,2-propyleneglycol, 1-methoxy-2-propanol, phenoxypropanol and phenoxyethanol. 11.Method of increasing the stability and service life of industrialproducts containing industrial preservatives selected from the groupconsisting of container preservatives, fuel additives, cutting fluidpreservatives, preservatives which have been mixed with water, emulsionsand dispersions in the coatings industry or in metal working, householdproducts, and cosmetics, which comprises adding a biocidally effectiveamount of the composition of claim 1 as an active agent to theindustrial product.
 12. Industrial product which comprises as an activeagent, a biocidally effective amount of the composition of claim 1 saidindustrial product including industrial preservatives selected from thegroup consisting of container preservatives, fuel additives, cuttingfluid preservatives, preservatives which have been mixed with water,emulsions and dispersions in the coatings industry or in metal working,household products, and cosmetics.
 13. The industrial product accordingto claim 12, wherein the composition is present from 1 to 10% by weight.14. The industrial product according to claim 13, wherein thecomposition is present from 2 to 5% by weight.